Brains II

Brain stem from upper spinal cord to pyramids just inside the Foramen Magnum Two egg shaped thalamus sides are at the top Red nucleus peeking out below the left thalamus. The trigeminal thick arms reach forward with fingers of the branches covering most of facial sensation.

Looking from inside we see the shallow 4 th ventricle whose roof is cerebellum and sides cerebellar peduncles. The 5 th cranial nerve nuclear components ring the floor of this ventricle.

We can see the embryonixc early tubulation plane quite well here. In conditions of slowed infolding the eyes are wider apart. Theere may be clefts of the palate. The incompletely infolder 4 th ventricle looks like a cystic enlargement of the tubular canal and is often described as Arnold Chiari cyst.